move MergeBuckets into component-base so we can properly support it for static-analysis

hack/verify-prometheus-imports.sh

@@ -43,6 +43,7 @@ allowed_prometheus_importers=(
   ./staging/src/k8s.io/component-base/metrics/prometheusextension/weighted_histogram.go
   ./staging/src/k8s.io/component-base/metrics/prometheusextension/weighted_histogram_test.go
   ./staging/src/k8s.io/component-base/metrics/prometheusextension/weighted_histogram_vec.go
+  ./staging/src/k8s.io/component-base/metrics/buckets.go
   ./staging/src/k8s.io/component-base/metrics/collector.go
   ./staging/src/k8s.io/component-base/metrics/collector_test.go
   ./staging/src/k8s.io/component-base/metrics/counter.go

staging/src/k8s.io/component-base/metrics/buckets.go

@@ -0,0 +1,43 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+// DefBuckets is a wrapper for prometheus.DefBuckets
+var DefBuckets = prometheus.DefBuckets
+
+// LinearBuckets is a wrapper for prometheus.LinearBuckets.
+func LinearBuckets(start, width float64, count int) []float64 {
+	return prometheus.LinearBuckets(start, width, count)
+}
+
+// ExponentialBuckets is a wrapper for prometheus.ExponentialBuckets.
+func ExponentialBuckets(start, factor float64, count int) []float64 {
+	return prometheus.ExponentialBuckets(start, factor, count)
+}
+
+// MergeBuckets merges buckets together
+func MergeBuckets(buckets ...[]float64) []float64 {
+	result := make([]float64, 1)
+	for _, s := range buckets {
+		result = append(result, s...)
+	}
+	return result
+}

staging/src/k8s.io/component-base/metrics/histogram.go

@@ -23,19 +23,6 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
-// DefBuckets is a wrapper for prometheus.DefBuckets
-var DefBuckets = prometheus.DefBuckets
-
-// LinearBuckets is a wrapper for prometheus.LinearBuckets.
-func LinearBuckets(start, width float64, count int) []float64 {
-	return prometheus.LinearBuckets(start, width, count)
-}
-
-// ExponentialBuckets is a wrapper for prometheus.ExponentialBuckets.
-func ExponentialBuckets(start, factor float64, count int) []float64 {
-	return prometheus.ExponentialBuckets(start, factor, count)
-}
-
 // Histogram is our internal representation for our wrapping struct around prometheus
 // histograms. Summary implements both kubeCollector and ObserverMetric
 type Histogram struct {

test/instrumentation/decode_metric.go

@@ -480,15 +480,54 @@ func (c *metricDecoder) decodeBucketFunctionCall(v *ast.CallExpr) ([]float64, er
 	if functionImport.String() != c.kubeMetricsImportName {
 		return nil, newDecodeErrorf(v, errBuckets), true
 	}
-	firstArg, secondArg, thirdArg, err := decodeBucketArguments(v)
-	if err != nil {
-		return nil, err, true
-	}
 	switch functionName {
 	case "LinearBuckets":
+		firstArg, secondArg, thirdArg, err := decodeBucketArguments(v)
+		if err != nil {
+			return nil, err, true
+		}
 		return metrics.LinearBuckets(firstArg, secondArg, thirdArg), nil, true
 	case "ExponentialBuckets":
+		firstArg, secondArg, thirdArg, err := decodeBucketArguments(v)
+		if err != nil {
+			return nil, err, true
+		}
 		return metrics.ExponentialBuckets(firstArg, secondArg, thirdArg), nil, true
+	case "MergeBuckets":
+		merged := []float64{}
+		for _, arg := range v.Args {
+			switch argExpr := arg.(type) {
+			case *ast.CompositeLit:
+				fs, err := decodeListOfFloats(argExpr, argExpr.Elts)
+				if err != nil {
+					return nil, err, true
+				}
+				merged = append(merged, fs...)
+			case *ast.CallExpr:
+				se, ok = argExpr.Fun.(*ast.SelectorExpr)
+				if ok {
+					functionName := se.Sel.String()
+					functionImport, ok := se.X.(*ast.Ident)
+					if !ok {
+						return nil, newDecodeErrorf(v, errBuckets), true
+					}
+					if functionImport.String() != c.kubeMetricsImportName {
+						return nil, newDecodeErrorf(v, errBuckets), true
+					}
+					firstArg, secondArg, thirdArg, err := decodeBucketArguments(argExpr)
+					if err != nil {
+						return nil, err, true
+					}
+					switch functionName {
+					case "LinearBuckets":
+						merged = append(merged, metrics.LinearBuckets(firstArg, secondArg, thirdArg)...)
+					case "ExponentialBuckets":
+						merged = append(merged, metrics.LinearBuckets(firstArg, secondArg, thirdArg)...)
+					}
+				}
+			}
+		}
+		return merged, nil, true
 	}
 	return nil, nil, false
 }

test/instrumentation/testdata/pkg/kubelet/metrics/metrics.go

@@ -488,6 +488,21 @@ var (
 			StabilityLevel: metrics.BETA,
 		},
 	)
+
+	NetworkProgrammingLatency2 = metrics.NewHistogram(
+		&metrics.HistogramOpts{
+			Subsystem: "kube_proxy",
+			Name:      "network_programming_duration_seconds2",
+			Help:      "In Cluster Network Programming Latency in seconds",
+			Buckets: metrics.MergeBuckets(
+				metrics.LinearBuckets(0.25, 0.25, 2), // 0.25s, 0.50s
+				[]float64{1, 5, 10, 59},              // 1s, 2s, 3s, ... 59s
+				metrics.LinearBuckets(60, 5, 12),     // 60s, 65s, 70s, ... 115s
+				metrics.LinearBuckets(120, 30, 7),    // 2min, 2.5min, 3min, ..., 5min
+			),
+			StabilityLevel: metrics.BETA,
+		},
+	)
 )
 
 var registerMetrics sync.Once

test/instrumentation/testdata/test-stable-metrics-list.yaml

@@ -84,6 +84,37 @@
   - 240
   - 270
   - 300
+- name: network_programming_duration_seconds2
+  subsystem: kube_proxy
+  help: In Cluster Network Programming Latency in seconds
+  type: Histogram
+  stabilityLevel: BETA
+  buckets:
+  - 0.25
+  - 0.5
+  - 1
+  - 5
+  - 10
+  - 59
+  - 60
+  - 65
+  - 70
+  - 75
+  - 80
+  - 85
+  - 90
+  - 95
+  - 100
+  - 105
+  - 110
+  - 115
+  - 120
+  - 150
+  - 180
+  - 210
+  - 240
+  - 270
+  - 300
 - name: certificate_manager_client_ttl_seconds
   subsystem: kubelet
   help: Gauge of the TTL (time-to-live) of the Kubelet's client certificate. The value